This application is based on patent application Ser. No. 11-316109 filed Nov. 5, 1999 in Japan, the content of which is incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to a card connector for receiving an IC card such as memory card and more specifically to a card connector with an erroneous insertion prevention mechanism which, when the IC card is inserted in an inappropriate state, for example upside down, prevents the IC card from being inserted into a properly inserted position or connected position.
2. Description of the Related Art
Today the memory capacity is rapidly growing thanks to the remarkable advance of electronic circuit integration technology and there is a growing trend for using thin, small IC cards in the recording of various information such as characters, video and audio. Under this circumstance a variety of connectors for connecting the IC cards and electronic devices are being proposed and implemented.
FIG. 15A and FIG. 15B show one example of currently proposed IC card 1. As shown in the FIG., the IC card 1 has a card body 2 incorporating an IC in an almost rectangular case and a plurality of contacts 3 connecting to the IC in the card body 2 and leading out from the card body 2 to an external front end of the body 2. The card body 2 has a raised surface portion 4a protruding outwardly on its back surface 4 and also a notched portion 5 at one corner.
The raised surface portion 4a is rectangular in shape with its width between the outer side surfaces set smaller than a width between outer side surfaces of the card body 2. On the back surface 4 side, steps are formed between the raised surface portion 4a and other surfaces, i.e., recessed surface portions 4b. The raised surface portion 4a shown here includes outer end faces 6a of a plurality of separation walls 6 formed in the front portion of the back surface 4 of the card body 2 to separate contacts 3 from one another. The contacts 3 are securely attached with the recessed surface portions 4b between the separation walls 6.
The notched portion 5 is formed by cutting one corner of the front part of the card body 2 at angle, which makes the front part of the card body 2 asymmetric with respect to the direction of card insertion (X direction).
FIG. 16 shows a card connector 10 for holding the IC card. The card connector 10 has a connector body 11 for holding the IC card 1 so that it can be inserted and retracted, and also electric contacts 12 for making electric contact with the IC card 1 inserted into the connector body.
The connector body 11 has side portions 13, a bottom portion 14, and a top plate portion 15. The side portions 13 have guide surfaces 13a for guiding side surfaces of The bottom portion 14 has support surfaces 14a for supporting the back surface 4 of front surface 7 of the IC card 1 and stepped portions 14b that engage the raised surface portion of the IC card so that the raised surface portion 4a can be moved in the direction of IC card insertion and retraction. The top plate portion 15 keeps the IC card 1 from floating up. The electric contacts 12 are disposed to correspond to the contacts 3 of the IC card 1 and held on the bottom portion 14 like cantilevered springs.
The connector body 11 is placed at a predetermined position on a printed circuit board of an electronic device, with the lower end portions of the electric contacts 12 soldered to predetermined conductive portions of the printed circuit board.
When the IC card 1 is to be connected to the card connector 10 of the above construction, it is inserted into the insertion direction (X direction) with the front surface 7 facing up, the back surface 4 supported on the support surfaces 14a and both of the outer side surfaces of the IC card 1 guided by both of the guide surfaces 13a of the connector body 11. At this time, the raised surface portion 4a formed on the back surface 4 of the IC card 1 engages the stepped portions 14b of the bottom portion 14 of the connector body 11 as the IC card 1 is inserted.
Then, when the front end portion of the IC card 1 engages an abutment portion 16 of the connector body 11 (see FIG. 19), the contacts 3 contact the electric contacts 12, thus completing the connection (see FIG. 17). In this insertion operation, the IC card 1 is prevented from floating upward and getting dislocated by the under surface of the top plate portion, so anyone can perform an insertion and connection operation easily and correctly.
In the connector shown in FIG. 16, as long as the IC card 1 is oriented correctly while being inserted, the connection to the card connector 10 can easily and reliably performed. When the IC card 1 is wrongly oriented and inserted, the card connector may be damaged. This is the problem with the conventional card connector that degrades the operability.
For example, when the IC card 1 is inserted upside down, as shown in FIG. 18, the raised surface portion 4a formed at the bottom of the IC card 1 and protruding upward abuts back surface 4, the rear end of the top plate portion 15, as shown in FIG. 19. This state, however, is not a completely inserted state and there is a chance of the user further pushing the card with force.
In this case, because the raised surface portion 4a projects slightly above the under surface of the top plate portion 15 as shown in FIG. 19, the IC card 1, when applied with a strong push, is forcibly inserted between the bottom portion 14 and the top plate portion 15 of the connector body 11, as shown in FIG. 20, deforming the top plate portion 15.
In the event of such a trouble, the side portions 13 of the IC card 1 are also deformed along with the top plate portion 15, exerting a load on soldered fittings on the side portions 13 of the connector body 11 used to secure the connector to the printed circuit board and also on soldered portions of the contacts, which in turn causes the soldered portions to come off, degrading the connection reliability of the connector.
The present invention has been accomplished to overcome the aforementioned problems with the conventional card connector and provides a highly reliable card connector capable of preventing the IC card from being inserted in an improperly oriented condition and thereby forestalling damages due to inappropriate insertion of the IC card.
To solve the above problems the present invention has the following construction. That is, this invention is characterized by a card connector having a connector body for removably holding an inserted IC card formed with a raised surface portion on a back surface side and electric contacts for making electrical contact with the IC card inserted in the connector body, the connector body comprising: side portions having card side surface guiding surfaces to guide side surfaces of the inserted IC card; a bottom portion having a support surface to support a front surface or back surface of the inserted IC card and stepped portions to engage the raised surface portion formed on the back surface so that the raised surface portion can be moved in an IC card insertion/retraction direction when the back surface of the IC card is supported on the support surface; a top plate portion disposed opposite the bottom portion to prevent the inserted IC card from floating upward; and an urging means provided in the connector body to urge the IC card upward at a predetermined position with respect to the card insertion direction; wherein the top plate portion having: a under surface side guiding surface disposed opposite the front surface of the IC card to guide the front surface; and a blocking portion to, when the front surface of the IC card is supported on the support surface, engage the raised surface portion of the IC card at a predetermined blocking position to prevent the IC card from being moved forward from the blocking position, the blocking portion being disposed in front, with respect to the IC card insertion direction, of the predetermined position where the IC card is urged by the urging means.
The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.